Noise reduction member and system

ABSTRACT

There is disclosed a noise reduction member. Preferably, the noise reduction member is employed for sealing or baffling within a pillar or other structure of an automotive vehicle, although not required.

CLAIM OF PRIORITY

This application claims the benefit of the filing date of U.S.Provisional Application Nos. 60/688,255 filed Jun. 7, 2005.

FIELD OF THE INVENTION

The present invention relates generally to a member for providing noisereduction to an article of manufacture (e.g., an automotive vehicle)through baffling, sound absorption, a combination thereof or the like.

BACKGROUND OF THE INVENTION

For many years, industry (e.g., the transportation industry) has beenconcerned with designing members for providing noise reduction (e.g.,baffling, sound absorption, combinations thereof or the like) toarticles of manufacture such as automotive vehicles. Typically, suchmembers include expandable materials, which may or may not be supportedby carrier members, and which, upon expansion, form seals, baffles,sound absorption systems or the like in one or more cavities of anarticle of manufacture. Design of such members can involve multiplecompeting characteristics For example, it may be desirable for themembers to be relatively lightweight while still maintaining the abilityto exhibit a relatively high degree of noise reduction. Other desirablecharacteristics for the members can include, without limitation, lowcost, ease of assembly, ease of manufacture compatibility with thearticles of manufacture to which the members are applied and otherfactors. Thus, the present invention provides a noise reduction memberand system that exhibits at least one, but preferably multiple desirablecharacteristics.

SUMMARY OF THE INVENTION

The present invention is directed to a noise reduction member. Themember typically includes a carrier member and an expandable material.Preferably, the carrier member includes one or more walls for guidingthe expansion of the expandable material and will also typically includean attachment for locating the noise reduction member at leasttemporarily relative to a structure of an article of manufacture. Theexpandable material is preferably a relatively high expansion material.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and inventive aspects of the present invention will becomemore apparent upon reading the following detailed description, claims,and drawings, of which the following is a brief description:

FIG. 1 is a perspective view of an exemplary member in accordance withan aspect of the present invention.

FIG. 2 is another perspective view of the exemplary member of FIG. 1.

FIG. 3 is a cut away side view of the exemplary member of FIGS. 2 and 3applied to a structure of an automotive vehicle.

FIG. 4 is a cut away side view of the exemplary member and structure ofFIG. 3 after expansion of an expandable material of the member to forman exemplary system.

FIG. 5 is a magnified view of a portion of the exemplary system of FIG.4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is predicated upon the provision of a membersuitable for providing noise reduction to one or more structures of anarticle of manufacture typically by providing baffling, soundabsorption, sound deflection, a combination thereof or the like to thestructures. Together, the one or more structures and the member form asystem or assembly that is generally desirable for the article ofmanufacture because of the functional attributes (e.g., noise reduction,baffling, sealing, strength, reinforcement combinations thereof or thelike) provided by the member. It is additionally contemplated that themember may be able to provide structural reinforcement to the structureof an article of manufacture.

It is contemplated that the member may be employed in conjunction with avariety of structures of various articles of manufacture such as boats,trains, buildings, appliances, homes, furniture or the like. It has beenfound, however, that the member is particularly suitable for applicationto structures or assemblies of transportation vehicles such asautomotive vehicles. Generally, it is contemplated that the member maybe applied to various structures such as components of a body, a frame,an engine, a hood, a trunk, a bumper, a pillar combinations thereof orthe like of an automotive vehicle.

The noise reduction member typically includes one or more of thefollowing:

i) a carrier member that typically includes at least one, but morepreferably two, three or more walls, one of which typically includes athrough-hole extending therethrough, although not required;

ii) an expandable member connected to the carrier member wherein theexpandable material is typically located adjacent (e.g., between) afirst and/or a second wall of the carrier member, although again, notrequired; and

iii) an attachment (e.g., a fastener) connected to the carrier memberthe expandable material or both.

Upon expansion, the expandable material can, if desired, be configuredto substantially entirely fill a section of a cavity in which the memberhas been placed. In such an embodiment, the expandable materialtypically expands to form a foam that spans across a cross-section ofthe cavity for inhibiting or prohibiting the passage of mass (e.g., dustand debris) and or sound (e.g., noise) through the cavity.

The member of the present invention is typically or primarily employedfor sound (e.g., noise) reduction within an article of manufacture(e.g., used as a baffle within a cavity of an automotive vehicle). it iscontemplated, however, that the member may be additionally oralternatively used as a separator, a reinforcement, a hole plug, ablocking member, a combination thereof or the like.

The member of the present invention is typically comprised of a carriermember and at least one mass of an expandable material connected to andpreferably at least partially supported by the carrier member. Thecarrier member typically includes at least one, but preferably aplurality of walls and the at least one or plurality of walls typicallydefine a cavity suitable for receipt of at least one mass of expandablematerial.

Referring to FIGS. 1 and 2, there is illustrated an exemplary member 10according to the present invention. The member 10 includes a carriermember 12 and a mass 14 of expandable material connected to the carriermember 12. Generally, the carrier member 12 and the mass 14 ofexpandable material may be shaped in a variety of configurations withinthe scope of the present invention. Thus, the specific shapes andconfigurations of the carrier member 12 and the mass 14 of expandablematerial in the figures and description should not limit the presentinvention, unless otherwise specifically stated.

The carrier member 12 is shown to have a first or top wall 20, a secondor bottom wall 22 and a third or side wall 24 interconnecting the topand bottom walls 20, 22. The first wall 20 opposes the second wall 22and, in the embodiment shown, the first wall 20 is substantiallyparallel to the second wall 22. Moreover, the first wall 20, the secondwall 22 and the side wall 24 are each substantially planar, althoughthey may be contoured if needed or desired.

Generally, the walls 20, 22, 24 or the carrier member 12 define a cavity30 suitable for receipt of the mass 14 of expandable material. In theparticular embodiment illustrated, the first wall 20 and the second wall22 (or the planes in which they are disposed) extend away, at skew(e.g., perpendicular) angles 34, 36 relative to the side wall 24 (or theplane in which it is disposed). In this configuration, the first wall20, the second wall 22 and the third wall 24 form a C-shape therebydefining the internal cavity 30.

It should also be noted that an opening 40 is defined in the carriermember 12 and particularly in the third wall 24 of the carrier member12. The particular opening 40 shown is illustrated as a generallyrectangular through-hole that extends through the third wall 24 or thecarrier member 12.

Typically, although not necessarily required, the member of the presentinvention will include one or more fasteners or attachments which may beconnected to the carrier member, the expandable material or both. Assuch, the fastener or attachment may be formed, molded or shaped of thesame material of the carrier member and/or the expandable material or,alternatively, may be a separate member that is attached or connected toone or both of the expandable material and the carrier member. Theattachment may also be an attachment medium such as an adhesive ormagnetic medium.

It is also contemplated that any fastener of the present invention maybe formed in a variety of configurations. Examples include, withoutlimitation, arrowhead fasteners, clip, rivets, interlocking mechanisms,combinations thereof or the like.

The illustrated member 12 includes a fastener 44 attached to andintegrally formed of the same material of the carrier member 12. Thefastener 44 is illustrated as a flange 46 that opposes a substantialportion of the opening 40 in the side wall 24. The fastener 44 includesa first generally rectangular portion 50 extending outwardly away fromthe carrier member 12, a second generally rectangular portion 52cantilevered and extending downwardly away from the first portion 50 anda third generally rectangular portion 54 extending outwardly away fromthe second portion at an angle.

The carrier member 12 can also include one or more securement flanges60. Such flanges 60 typically extend toward and/or into the cavity 30defined by the carrier member 12, although not required. The exemplaryillustrated carrier member 12 includes at least one flange 60 extendinginto and/or toward the cavity 30 from each of the top wall 20 and thebottom wall 22 of the carrier member 12. More particularly, both the topwall 20 and bottom wall 22 include a pair of flanges 60 shown as barbsextending into and/or toward the cavity 30 from adjacent opposite edgesof each of the top wall 20 and the bottom wall 22 of the carrier member12.

The carrier 12 including the walls 20, 22, 24 and the fastener orattachment 44 may be integrally formed of a singular material or may beseparately formed of different materials. Materials for the carriermember and its respective components may be formed of or include,without limitation, metals, polymeric materials (e.g., nylon, polyamide,polyester, polypropylene, polyethylene or others), which may be filledor unfilled (e.g., filled with glass reinforcement fibers) or othermaterials. As such, the carrier member, may be processed and/or formedusing metal forming techniques such as bending, extruding or the likeand may be processed and/or formed using polymer shaping techniques suchas molding (e.g., blow molding, injection molding compression molding orthe like). In one preferred embodiment the carrier is integrally formedof a metal material such as aluminum, steel or the like and is stampedinto its desired shape (e.g., the shape shown is FIGS. 1-3).

As discussed, the mass of expandable material may be shaped in a varietyof different configurations and there may be multiple different massesof expandable material. Preferably, at least one mass of expandablematerial is located at least partially (e.g., at least 10% of the volumeof the mass) or substantially entirely (e.g., at least 70%, 80%, 90% ormore) in the cavity of the carrier member, although not required. It isalso preferable for, at least one mass of expandable material to belocated at least partially (e.g., at least 10% of the volume of themass) or substantially entirely (e.g., at least 70%, 80%, 90% or more)between the first wall 20 and second wall 22 of the carrier member 12,although not required.

The mass 14 of FIGS. 1-3 extends along an axis 64 of elongation and hasat least one dimension (D) extending substantially parallel to that axis64. That dimension (D) can be selected from length, height or otherdimension. In one embodiment, any and/or every diameter of the mass ofexpandable material taken perpendicular to the elongated axis 64 areshorter than the dimension (D). As used herein, diameter is meant toinclude any line segment extending from one surface of the mass toanother surface of the mass.

It is contemplated that the mass of expandable material may be formedinto a variety of shapes and configurations. The walls of the mass maybe planar or contoured and the mass may be geometric or non-geometric ora combination thereof. In the embodiment illustrated, the mass 14 ofexpandable material is generally shaped as a polyhedron having sidesthat are respectively square and rectangular.

The volume of the mass of expandable material may be relatively large orrelatively small prior to expansion thereof. As such, the size or volumeof the mass should not be limited unless otherwise specifically stated.Generally, however, preferred embodiments of the invention have a massof expandable material with a volume that is greater than about 0.5 cm³,more typically greater than about 1.0 cm³, and even more typicallygreater than about 1.5 cm³ and a volume that is less than about 10 cm³,more typically less than about 4.0 cm³ and even more typically less thanabout 2.0 cm³.

A variety of expandable materials may be used for the mass of expandablematerial of the present invention. In one embodiment, the material maybe formed of a heat activated material and may flow, cure (e.g., bethermosettable), foam or a combination thereof upon exposure to heat.The expandable material may be generally dry to the touch andsubstantially tack free or may be tacky and, in either situation, may beshaped in any form or desired pattern, placement, or thickness, but ispreferably of substantially uniform thickness. Exemplary expandablematerials are L-7102 and L-7220 foam available through L&L Products,Inc. of Romeo, Mich. Another exemplary expandable material is disclosedin U.S. patent application titled “Expandable Material”, Ser. No.10/867,835, filed on Jun. 15, 2004 and incorporated herein by referencefor all purposes.

Though other heat-activated materials are possible, a preferred heatactivated material is an expandable polymer or plastic, and preferablyone that is foamable. Particularly preferred materials are epoxy-based,acrylate-based or acetate-based foams, which may be structural, sealing,sound damping, sound absorbing, sound attenuating or a combinationthereof. For example, and without limitation, the foam may be anepoxy-based material, including an ethylene copolymer or terpolymer thatmay possess an alpha-olefin. As a copolymer or terpolymer, the polymeris composed of two or three different monomers, i.e., small moleculeswith high chemical reactivity so that are capable of linking up withsimilar molecules.

A number of epoxy-based or otherwise based sealing, baffling or acousticfoams are known in the art and may employed in the present invention. Atypical foam includes a polymeric base material, such as an epoxy resinor ethylene-based polymer which, when compounded with appropriateingredients (typically a blowing and curing agent), expands and cures ina reliable and predictable manner upon the application of heat or theoccurrence of a particular ambient condition. From a chemical standpointfor a thermally-activated material, the structural foam is usuallyinitially processed as a flowable thermoplastic material before curing.It will cross-link upon curing, which typically makes the materialincapable of further flow (e.g., thermoset).

One advantage of the preferred foam materials over prior art materialsis that the preferred materials can be processed in several ways. Thepreferred materials can be processed by injection molding, extrusion,compression molding or with a mini-applicator. This enables theformation and creation of part designs that exceed the capability ofmost prior art materials.

While preferred materials have been disclosed, other materials may beused as well, particularly materials that are heat-activated orotherwise activated by an ambient condition (e.g. moisture, pressure,time, chemical reaction or the like) and cure in a predictable andreliable manner under appropriate conditions for the selectedapplication. Of course, the material may also be formed ofnon-activatable materials, non-expandable materials or otherwise. Thus,upon activation, the material may soften, cure and expand; soften andcure only; cure only; soften only; or may be non-activatable.

One example of an expandable material is the epoxy based resin disclosedin U.S. Pat. No. 6,131,897, the teachings of which are incorporatedherein by reference. Some other possible materials include, but are notlimited to, polyolefin materials, copolymers and terpolymers with atleast one monomer type an alpha-olefin, phenol/formaldehyde materials,phenoxy materials, and polyurethane materials with high glass transitiontemperatures. See also, U.S. Pat. Nos. 5,766,719; 5,755,486; 5,575,526;and 5,932,680, (incorporated by reference). In general, desiredcharacteristics of the material can include adhesion durabilityproperties or the like, although such properties are not necessarilyrequired. Generally, it is desirable that the material does notgenerally interfere with the materials systems employed by automobilemanufacturers or other manufactures.

Other exemplary expandable materials can include combinations of two ormore of the following: epoxy resin, polystyrene, styrenebutadiene-styrene (SBS) block copolymer, butadiene acrylo-nitrilerubber, amorphous silica, glass microspheres, azodicarbonamide, urea,dicyandiamide. Examples of such materials are sold under the tradenameSIKAELASTOMER, SIKAREINFORCER and SIKABAFFLE and are commerciallyavailable from the Sika Corporation, Madison Heights, Mich.

In applications where the material is a heat activated, thermallyexpanding and/or foaming material, an important consideration involvedwith the selection and formulation of the material forming the foam isthe temperature at which a material reaction or expansion, and possiblycuring, will take place. Typically, certain expandable materialingredients become reactive at higher processing temperatures, such asthose encountered in an automobile assembly plant, when the material isprocessed and/or activated along with the automobile components atelevated temperatures or at higher applied energy levels, e.g., duringpaint or e-coat baking or curing steps. While temperatures encounteredin an automobile assembly operation may be in the range of about 148.89°C. to 204.44° C. (about 300° F. to 400° F.), body and paint shopapplications are commonly about 93.33° C. (about 200° F.) or slightlyhigher. If needed, various different blowing agents or blowing agentactivators can be incorporated into the composition to cause expansionat different temperatures outside the above ranges. Generally, suitableexpandable materials have a volumetric range of expansion ranging fromapproximately 0 to over 1000 percent. For example a mass of expandablematerial may expand to form a foam that occupies a volume that is (e.g.,is at least partially located within) at least 150%, 200%, 500%, 1000%,1500%, 2000% or 3000% of the volume occupied by the original unexpandedmass of expandable material.

The material or medium may be at least partially coated with an activepolymer having damping characteristics or other heat activated polymer,(e.g., a formable hot melt adhesive based polymer or an expandablestructural foam, examples of which include olefinic polymers, vinylpolymers, thermoplastic rubber-containing polymers, epoxies, urethanesor the like) placed along the mold through the use of baffle technology;a die-cast application according to teachings that are well known in theart; pumpable application systems which could include the use of abaffle and bladder system; and sprayable applications.

Formation

The noise reduction member of the present invention may be formedaccording to a variety of protocols. Generally, the mass of expandablematerial is placed adjacent one or more walls of the carrier member. Itis contemplated that the carrier member may be formed to its desiredshape followed by placement of the mass of expandable material at leastpartially within or more substantially entirely within the cavity formedby the carrier member. In the illustrated embodiment, the carrier member12 is formed to shape and the mass 14 is automatically,semi-automatically or manually placed within the cavity 30 of thecarrier member 12. As can be seen, the flanges 60 of the carrier member12 contact and/or extend into the mass 14 of expandable material formaintaining the position of the mass 14 relative to the carrier member12.

In alternative embodiments, it is contemplated that the carrier membermay formed (e.g., bent or otherwise shaped) about the mass of expandablematerial such that the mass of expandable material is automaticallylocated within the cavity defined by the carrier member. In such anembodiment, a machine such as a press may be employed to press fit thecarrier member about the mass of expandable material.

As another alternative the mass of expandable material and carriermember are formed and/or shaped substantially simultaneously or at closeproximity in time relative to each other (e.g., within 30 minutes, 2minutes or even 10 seconds). For example, material of the carrier memberand the expandable material may be co-extruded and then the coextrusionmay be cut to shape the noise reduction member.

Application

The noise reduction member nay be applied to a variety of locations upona variety of structures of a variety of articles of manufacture.Typically, the attachment of the noise reduction member will be employedfor attaching the noise reduction member to a structure of an article.

For automotive vehicles, the noise reduction member can be locatedwithin cavities that are at least partially or substantially entirelyformed by automotive vehicle structures such as frame members, bodymembers, roof rails, closure panels (e.g., doors, hoods, trunk lids,tail gates, etc.), or others. In one embodiment, the noise reductionmember is particularly suitable for application, acoustic dampening,baffling, sealing or a combination thereof within or adjacent a pillar(e.g., a forward or A-pillar, a central or B or C-pillar or a rearwardor C or D-pillar) of an automotive vehicle. For example, the baffle maybe located adjacent or within a cavity formed by the pillar forprohibiting or inhibiting the passage of material or sound through thecavity.

Generally, after location of the noise reduction member relative to astructure, the mass of expandable material is typically activated toflow, expand, foam, cure, harden, adhere or any combination thereof. Iflocated within a cavity of a structure, the mass is typically activatedto expand or foam to substantially fill and span a cross-section of thecavity of the structure for prohibiting or inhibiting the passage ofmaterial or sound through the cavity.

In FIG. 3, the exemplary member 10 has been placed in a cavity 70 of astructure 72 of an automotive vehicle. The structure 72 illustrated is aframe structure or pillar of a vehicle but it shall be understood thatthe structure may be any of structures discussed herein and otherstructures as well.

For at least temporarily locating the member 10 in the cavity 70, thefastener 44 of the member 10 has been attached to the structure 72. Inthe illustrated embodiment, the flange 46 of the fastener 44 of thenoise reduction member 10 is extended into and through an opening 78(e.g., a through-hole) in the structure 72 for attaching the member 10to the structure. As shown, a cavity 80 is defined between the fastener44 and the mass 14 of expandable material, the carrier member 12 or bothfor receiving an edge 82 of a panel 84 of the structure 72 uponinsertion of the fastener into the opening 78 of the structure 72. Also,as shown, the cavity 80 includes a widened receiving portion 88 definedby the third outwardly angled portion 54 of the fastener 44 forassisting in extending the fastener 44 through the opening 78 andreceiving the edge 82. As can be seen, the member 10 has been located inthe cavity 70 such that the first or top wall 20 is directly adjacentand/or below an opening 90 (e.g., a through-hole) in the structure 72and/or the second or bottom wall 22 is directly adjacent and/or aboveanother opening 92 (e.g., through-hole) in the structure 72.

Upon activation of the mass 14 of expandable material, the mass 14 foamsand expands within the cavity 70 of the structure 72. As shown in FIGS.4 and 5, the mass 10 is expanded to form or expanded a foam material 96that adheres to walls of the structure 72 defining the cavity 70 andexpands such that the foam material 96 substantially fills and span across-section 98 of the cavity 70 of the structure 72 for prohibiting orinhibiting the passage of material or sound through the cavity 70. Inthis manner, the member 10 forms a noise reduction system 100 inconjunction with the structure 72. Advantageously, the opening or hole40 in the side wall 24 allows the foam material 96 to expand and/orextend through the opening 40 and connect with other portions of thefoam material 96 such that the foam material 96 more substantiallyentirely spans the cross-section 98 defined by a plane extendingoutwardly and into from the page at the line defining the cross-section98 to inhibit or prohibit passage of sound (e.g., noise) and mass ormaterials through the cavity.

As an added advantage, the first or upper wall 20 of the carrier member12 and/or the second or lower wall 22 of the carrier member 12 prohibitor at least inhibit the mass 14 of expandable material from expandingover and partially or substantially entirely covering the openings 90,92 of the structure 72 by the foam material 96. As can be seen, thewalls 20, 22 assist the expandable material in forming the foam material96 with cavities 110 that provide space about the openings 90, 92. Thus,these openings 90, 92 remain useful for allowing components such aswiring to extend into and through the openings 90, 92.

Unless stated otherwise, dimensions and geometries of the variousstructures depicted herein are not intended to be restrictive of theinvention, and other dimensions or geometries are possible. Pluralstructural components can be provided by a single integrated structure.Alternatively, a single integrated structure might be divided intoseparate plural components. In addition, while a feature of the presentinvention may have been described in the context of only one of theillustrated embodiments, such feature may be combined with one or moreother features of other embodiments, for any given application. It willalso be appreciated from the above that the fabrication of the uniquestructures herein and the operation thereof also constitute methods inaccordance with the present invention.

The preferred embodiment of the present invention has been disclosed. Aperson of ordinary skill in the art would realize however, that certainmodifications would come within the teachings of this invention.Therefore, the following claims should be studied to determine the truescope and content of the invention.

1. A noise reduction member, comprising: a structure of an automotivevehicle, the structure having a wall defining a first through-hole, asecond through-hole and a third through-hole; a carrier member having atop wall, a bottom wall and side wall interconnecting the top and bottomwalls, wherein: i) a rectangular through-hole is defined in the sidewall of the carrier member; ii) the top and bottom wall aresubstantially parallel to each other and generally oppose each other;iii) the top wall, the bottom wall and the side wall are eachsubstantially planar; iv) the top wall and the bottom wall extend away,at perpendicular angles relative to the side wall and cooperatively thetop wall, the bottom wall and the side wall define an internal cavity;v) the carrier member is formed substantially entirely of metal andincludes extensions; a mass of expandable material located substantiallyentirely in the cavity of the carrier member, extending along anelongated axis and having a dimension selected length or height parallelto that axis, wherein: i) any diameter of the mass of expandablematerial taken perpendicular to the elongated axis are shorter than thedimension; ii) the mass of expandable material is substantially entirelylocated between the top wall and the bottom wall; iii) the mass ofexpandable material is generally shaped as a polyhedron having sidesthat are rectangular; iv) the mass of expandable material is configuredto volumetrically expand to a volume that is at least 3000% of itsoriginal unexpanded volume; a fastener attached to the carrier member,the expandable material or both, the fastener being a flange thatopposes a substantial portion of the opening in the side wall, whereinthe fastener includes: i) a first generally rectangular portionextending outwardly away from the carrier member; ii) a second generallyrectangular portion cantilevered and extending downwardly away from thefirst portion; and iii) a third generally rectangular portion extendingoutwardly away from the second portion at an angle; wherein a cavity isdefined by the fastener and the expandable material, the carrier memberor a combination thereof for receiving an edge of a panel of a structureupon insertion of the fastener into an opening of the structure andwherein the cavity includes a widened receiving portion defined by thethird outwardly angle portion of the fastener and wherein the extensionsof the carrier member contact the expandable material for assisting inpositioning and maintaining the expandable material in a locationrelative to the carrier member and wherein the fastener extends throughthe first through-hole for locating the carrier member and theexpandable material within a cavity of the structure of the automotivevehicle such that the second through-hole is directly adjacent and abovethe top wall of the carrier member and the third through-hole isdirectly adjacent and below the bottom wall of the carrier member andwherein, upon expansion of the expandable material, the top wall shieldsthe second through-hole and the bottom wall shields the thirdthrough-hole from being covered by foam formed by the expandablematerial and wherein the top wall and bottom wall of the carrier memberextend less than half a distance across the cavity.